Signaling system



' Mayal, '1927.

l F. A. MILLER SIGNALING SYSTEM. Filed am iu. .i925

' 5 Sheets-$heet 1 f1 |p Y v bw,

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` ATTORNEYS ya F.A.M|L|.,ER.

SIGNALING s-'fsTM Filed June 11. 192s sheets-sheet 2 IN V EN TOR. Feng/Vf( 4. MLLE i ATTORNEYS.

F. A. MILLER SIGNALING SYSTEM Filed June 1,1', 1923 3 Sheets-Sheet 5 May 31.1927. f 1,639,962

F/G. 4- INVENToR. Haq/w( A. mfg/.ER

4, ATTORNEYS.

raireg ir-"riftV FRANK A., MILLER, or oAirLArin, oeLrFonnrA, Assrenon To sait vnnaricisco-SACRA- iviniv'ro RAILROADk 00.,.011 OAKLAND, CALIFORNIA, A coRroRATIoN ony CALI;-

FORNIA.

sreitALrNG SYSTEM.

.ippiianoy iea June 11, 1922. seriai No., eiiiigefs.'

This vinvention relates to ascheme Whered by an event, such as the arrival ot'a vehicle or train at any of a plurality ol'selected points, causes the transmission of a signallto a central location,'such as a train` dispatcher?s office. l

lTheA desirability otl transmitting ,such vsig'- y nals in a reliablev and simple-manner is evi dent; It is thus one of the objects ot' my invention'to provide a novel system-ot` signaling whereby these desirable resultsy mayY be readily accomplished.

In such systems itis advantageous to associate a certain signal With the signaling points, which is peculiar to it, so that the receipt of the signal at the dispatchers' oi .tice will show that a-train'has passed a ticular point. lt is oner of the objects otL my vinvention-,not only to transmit this intelli gence, but also the direction in which the train is proceeding. l

I accomplish these functions by the aid of relatively simple electric circuits. All' oi' the transmitting arrangements connect to av common circuit, so that` variations inl the currentfiow inA this circuit in a ipredete'rmined sequence, Wil-l aii'ect a receiver such as a tape recorder, in the dispatches'oitice. All; of` the signals, no mattei' from what )ointaiiect this commonl receivinv devicev 1 7 C and its operating circuit. VUnder such circumstances, there is apossibility that more than onetr'ain at any time Vwill cause they actuation of the recorder, and interference and con'l'usion would result; An important advantage of the use otmyl system-is that such inter-terence is obviated, and lthat they signals must come in succession, if necessary by delaying' some ojt. them temporarily.v

However none ot the si fnalsare ever su 3- pressed ythey may be. merelydelayed thev proper time interval topermit other signalsgeous Jiieatures, soi-neet Which With the foregoii'ig, will beset orthat length inthe lfollowingdescription, Where I- shall outline' in full that form of the invention which,` I have selected tor` illustration in tliefdraivf, ings accompanying and forming part. cifthe a present specification. Although Ii havey shown in the; drawings but one embodiment". of my invention, I do not desiretobe limited'thereto, since the invention as expressed; in the claims may be embodied in otherl forms also.

Referring to the drawings:

Figure -1 is avviring diagram of one' por#l tion oi a` system embodying my invention,

in Which is indicated the circuit connections Y Vbetween the train dispatchersoili'ce or receiving station; ,y n

Fig. '2 is avviring diagram of'tha't portionl of thek system Which includes the signaling' point, and an intermediate signaling` Vstationfarthest from the train dispatchersy oiiice orA receivingrpoint;

Fig, 3 is a side elevation of'o'ne termoli a' motor driven code Wheel/and its appurtenances, as they may be utilized atjinterine'- diate stations; and k Y,

Fig. 4 is an en d View of the device shown in Fig.'3. i i 1 v f Atthey signal receiving station, there may be a local receiving circuit including a; source of electricalenergy 11,telegraph 'rea lay'contacts l2, anda signal recording `or receiving device 13, preferably ajtime clock printer- This circuit is arranged to be eire'rgized upon making-oi'1 the relay contacts 12.V The relay 14, `iorperforming this func--v tion, is Operated inl response to thetransmission of codedsignals by a trainipassingl a distant point. 'The circuitv 'arrangement for performing this function will now be described.

lnthe present instance the relay 14 isar-` ranged to be operatedv by direct current'.`

froiny a"l battery l5 having tsfnegative pole grounded asat 16. Thefconnection 17 leads toia=telephonesystem, and infthis vWay thel direct current signaling impulses may useV the`r same Wiresfor one side oftheV signal Y that thetelephone. Wiresfmayibe yusedftor. the Y signal currents in an eh'icientV manner,l thef telephone; system ,is split yup .into inductivelylvcoupled sectiens, ,one suchsection` being iin Such telephone i VVVil ythe .wire .17, tori example from the receiving` coupled together. p the right hand end of the section underconi dicated by the wires 21 and 22', and the coils 19, 20,A 23, and 24. The coupling` is eiiectefl from one section-.to another *byA the aid oft these coils. Furthermore the points where the sections are coupled 4are chosen at locations vnear toV the signaling stations, soV that relay 14, may be readily connected to a point 18 central between the two coupling coils 19 and 20. It is thus evident that the Atelephone wires 21 and 22 form two paths in parallel for the signaling current between therelay 14 and a point 25 midway between the two coupling coils 23 and 24.

' The splitting up ot the telephone wires into sections oif'this sort does not in anyV wayv hinder the use of the telephone system, since theadjacent sections are all inductivcly Vrlhus the coils 19, 2O at sideration are coupled to coils 26, 27 of the next section to the right of thedispatchers station. the section, coils 23 and 24 are coupled Vto thecoils 28 and 29k ofthe next section to the lett. Such an arrangement may be obviously multiplied asneeded, in order te` provide as many tapping iii points such18,25, and 30 as desired for theproper interconnection oi all the pointsfwhen the passage of trainsV` but otv course thev saine scheme of connec' tions may` be used rfor stations even farther removed, as will become evident from the'. K The connection between the telephone sections includes wires 32 and 33,VK

description.

` aswell as a circuitcontrolling element, suoli as a relayv 34. The equivalent ot these connections exist at all stations, except that farthest from the dispatchersl oiiice. In this way, the telephone sections form a con- Vnected series ot wires between the signaling stations. DueV to the tact that the tapping iii points, such as 30, 25 and 18 are neutral as regards thetelephone system, no alternating current disturbance can vresult from utlizing these points. i Y

In order retransmit a :signal from station 31 tothe receiving device 18, I prefer to utilize a code wheel 35, which when rotated causes electrical Contact to bej made between the contacts 36, 37, and 40 in a predetermined order, depending uponthe number and ai'-` rangement of vtheY projections 38 on the code wheel 35,. One. of the contacts, such as 36, is connected to ground at 39, while the other two, 37 and 40, connect respectivelyto wires 32 and 33. 'Thecode wheel 35 is so arranged that its irst movement servesk to connect cena Similarly at the .lettA hand end of tacts 37 and 40 'i and thereby shert circuit relay 34', which controls' theoperation of the device to prevent it from being interi'ered with troniV other stations,once the code wheel The complete signaling circuit whenjcon y tact 36 is active,pmqay now be traced. Start ing at the right `hand terminal of source 15 in the train dispatchcrs oiiice, the signaling current flows through `grounded connection 16, through ground, to the station 31where it flows through grounded connection 39, contacts 36 and 40,1 connection33, point 25, where the circuit divides-onebranch includingcoil 23, wire 22, and Vcoil 19, the

vother including coil 24,'wire 21 andcoil 2O;A lat point 18 the circuit reunites, and thence continues through connection 17, relay 14, and to the lett hand terminal otbattery 15. The relay 14 in turn closes thewcircuit for the recorder 13. Y Y

F or each of the other stations also, a simi- -larset ot connections is Completed when sendingsignals,y the sole dilerence being that more than one inductively coupled telephone section is traversed bythe signaling eurent, and that the current also flows thr ugh relays such as 34 which are interposed between the sections.v V,All of these liiiterposed relays, corresponding to all. of the intervening stations, `are energized andA per-v form a controlling function, as has been intimated hereinbefore, the description of which it is inexpedient to set vriorth at this time. V

In order to necessary to rotate the code wheelv 35, and/igor accomplishing this result, I show a Vsmall electric motor 41, havingy a field winding 42 energized from any appropriate source. It

Y im

transmit the signalait is"V is ot course possibleto utilize other iorms of motive power. This motor is rendered activeautomatically in response to the pas-V sage of a train past the station', and Va signal. may thereby be` transmitted. The control of theinotor circuit may be effected by any approl'iriate device which is operated by the train; in the present instance I show a pair of normally closed switches 43- and 44, located near eachother along thetraclrand operated by the passage or a train. Such switches are usually inclosed in what/are termed track boxes, and are well-known inV the art of railway signaling. Twok such switches-are indicated',fin order to provide-y directional signaling;l that is a trainV com ing from right tolel't will operate switch 43 first, whileone on the vopposite direction will operate switch 44 first, and different signals may be produced by such an arrangement. l shallk now describe how a train coming from right to lett produces a signal, and shall afterwarddescribe how a different signal may be sent when the train is travelling in the opposite direction. Y,

In order to secure these eil'ects, control motor 4l by the track switches 43 and 44 in lows: from the positive terminal of battery 45, connection 47, switch43, relay 46,v and connections 43, 49, and 50 back to thenegative terminal of battery 45. Contacts 51, which are normally out, of engagement, close when this relay 464 becomes deenergized in response to the opening of the switch l43. These contacts in'turn cause the energization of one'ot the main control relays 52, the circuit for which may now be traced as follows: from the positive terminal of battery 45, connection 47, contacts l, connections 53 and 54, relay 52, and connection 55 back to the negative side ot the battery 45.

After the contacts'5l are completed, iny

the manner described, the relay 52 remains energized until after the signal is sent, even if the relay 46 picks' up its contact 5l in response to the clearing of thetrain pastv lThis result is accomplished.

the switch 43. by the aid oit' a holding circuit Afor relay 52, including the contacts 56 which are closed when relay 52 is energized. The

holding circuit may be traced as follows:

from the positive terminal of battery 45,

connection or, contacts 56, connection 58, a pair of spring contacts 59, connection 54, relay 52, connection 55, back to the negative terminaloit'1 battery 45.. The relay circuit thus stays closed until the spring contacts 59 separate, and this is accomplished only after thev code wheel completes its movement.l This result is obtained by providing a mechanical connectionv between these con-l tacts 59 and the code wheel 35, in a manner that will be described at length hereinafter.

Theprelay 52 may control a plurality of other sets -o't normally open contacts. Thus contacts 6i are in a circuit including a clutch magnet 62. This clutch, when energized serves to disconnect the motor 4ll from thev mitte d. Y y

is thus obtained. lt is to be noted that recode wheel 35,.sothat it is then incapable ot transmitting a signal. The `clutch is provided for thevery'important function of f preventing two stations `from transmitting signals atthe same time, and thearrangement is therefore such that while one station code wheel 35 is actuated, the clutches for other stations that may be attempting to signal are inactive,and remain sountil the line clears.4 How this is accomplished willy become evident from a tracing of the clutch magnet circuit, which is as follows: from the positive terminal of battery .connection 57, contacts 6l, contacts 63 of relay 34, connection 64, .clutch magnet 62, and connections 49 and 50, back to the negative terminal ot battery lt is to be noted that thiscircuit iscompleted only when relays 52 and 34are energized; and this con-.k

dition corresponds to an attempt by the local station to transmit a signal (causing relay 52 to be energized) .and to a transmissionv of a signal from another station (causing relay 34 to be energized). tromthe dstant station are started sooner than the code wheel 35 at this station, then it is evident that-relay 34, in pickingup and making contacts 63, will place the clutch magnet circuit in proper conditionl to be completed as soon as switch 43 lopens and relay52 is energizec. It however no disf tant station is sending av signal, then the clutch remains in its operative position, even after contacts 6l of relay 52 close. By provi-ding` these contacts 61 operated 'by ref l-ay 52, it isk assured that current through the clutch coil 62 may flow only upon an in; terference between stations, and not every time that a distal-1t signal is being trans- A corresponding'saving in current ing after` decnergizatio'n, Y so that itv may s If the signals SMV maintain the contacts 63 closed during the Y wholeV period o `signaling by the distantV station. l i

Relay contacts'65 and 66 serve to complete the circuit forv motor 4l,.and it clutch magnet 62 is deenergized, the codewheel 35 will bedriven `around once *toA transmit a. signal. T he motor circuit may be -traced as follows: from the positive terminal of battery 45, connection 57, contacts 65, connections 67 and 68, motor 4l, connections69 and 70, contacts 66 .and connection 50 to the negativeV side of battery45. lt is to benoted that the lower terminal. 71 ot' the motor is connectedl to the positive side of the battery 45, while Ilo the upper terminal72 is connected to the negative side. -Letus 'assume that for this 38 in this instance, which signal will be properly recorded as described herembefore at' the dispatcher-s oilice As soon asV wheel makes one revolution, it operates to open contacts 59 momentarily, and frelay 52 is restored to its normal kopen position. The motor circuit will then be interruptedfat the contacts ott this relay and the apparatus will returnto the position shown-in the figure.

.It is to be noted that upon passage of a train as described, the relay 52 is under all circumstances energized, and motor 41 1s operated, even if the clutch is inactive due to signaling,commenced at a distant station;r

and that this motor stays energized until contacts 59 open. lhere is thus an assurance that as soon as the distant station is through signaling, causing deenergization ot' relay 34, the motor 4l will be active until the code wheel 35 makes the'required angular movement. There is no danger of any signal being lost, due to this arrangement, the inactive condition being restored only after the signal is sent.

Tn case a train proceeds from left to right,

Y causing switch 44 to be first operated, the

I effects is similar to that already' described.

yarrangementis such that .the motorf4l rotates vin a reverse direction, and lcode wheel 35 is caused to senda reversedmessage, such as l2, instead of 2l asin theirst instance;

The operation of the system to secure these YA relay 73 is deenergized as soon as switch described.

44 opens. V'The circuit for this relay and the y switch 44 is in parallel to that of the relay 46 and switch 43, and need not be further Ttfisto be noted however, that these two relaysk are interlocked, so that if i tery 45.

one operates, the other cannot. In this Away .that relay alone is active which is first operated. The relay contacts 75 close'xas the relay 751s deenergized, and serve to complete the circuit forthe other control relay 76 through the following path: 'from the positive terminal of battery 45, connection 47, contacts 75, connection 77, Vrelay 76,'to the negati-ve terminal of battery 45. As soon as relay 76 picks'. up, a holding' Vcircuit is closed for it, which may be traced as fol- Vcircuit in casefrelay34 is 'energized in re-V sponse tothe transmission of a signal from a distant station. g Y

Contacts 82 and 83 control the motor 4l, the circuitv of which maybe traced as follows: from the positive terminal or battery l 45, connection 57, ycontacts S2, connections Ywhich is illustratediaFg. 2. tion there is a battery 87 grounded atv its 84 and 69, motor 4l, connection 68, contacts 83 and connection 50 baclr'to the negativeV terminal of battery 45. In this instance, the f upper terminal 72 of the'motor is connected` to the positive side ofthe battery, while the vor.

lower terminal is connected to the negative side. Themotor therefore, runsA in a direction opposite to that 'it relay 52y be en-A' crgized,and the code wheel is also reversed, and transmitsa reversed signal to indicate that the train `oassedv in a reverse direction.V l

y Due to the tact that relays 46 and 73 are inter-locked as indicated, only one of therelays 52 and 76 may be energized. In this way it is certain that there can be no signaling' interference, because the iirst of the two relays 73 and '46 to drop prevents the other from dropping. Furthermore, `due to the provision of contacts 371and 40 which short .circuit relay 84 whenever" code wheel 35 has moved tar enough to bring the lower p`or-.Y

tion of the signaling segment 85 undervcon-V tact spring,` 37., 1t 1s assured that no distantv simalingy station can operate the relay 34 andv cause the clutch magnet 62 to be 'energized toV disconnect the motor. y

The transmission of a signaling current fromtany intermediate station such. as V31 causes the energizationV of all otherV relays equivalent tor relay 34 thatare located betweenl the intermediate station and the. .dis-

patchers office, and thus prevents'them from sending a signal until the station 31 has ycompleted its signal.

sary toprovlde forthe energizationV oit all Y It is however, necesrelays such as 34 vfor all the stations, even those farther removed from the dispatchers oiice' than the sending station.y It is for this reason, mainly, that a slightly ditlerent system is provided at the end stationv'86,

At this stai negativeterminal as shown at 88,`so `as to oppose the similarly grounded battery vl5 at a the dispatchers oilice. The positive terminal is connected to a relay'89 Awhich is the equivalent of relay 841at the intermediate stations. This relay is connected to the telephone system at point 90 through a connection 91., normally closed' contacts 92 and 93, andlconncction 94.l LThus when any intermediate station such 3l is signaling, a current flow is." setup from its ground conlll) iis

nection 39, not only to tlie'dispatclhes eilice/ Y Lground 1G, butjalsojtothegrround 88 at the end station, thence through battery 87,1rel

89 and through the telephone system back tothe intermediate stations through alli-he intervening relays SLi-of those stations included between the end station Sti-and the signaling intermediate station A31. Thus 'all of the clutch magnetsare energized for all other stations. y

W'hen end station 8G is'to transmit a signalv by rotating vits code wheel 95, .thefirst vcover 9.

ire-30,962

'operation' performed by this Wheel is the opening 'of thecontact between springs 92 and 93, whereby the circuit for relay 89 is opened, and it is assured that the motor clutch Will not be renderedinactive. Con-V tinued rt'itation of wheel 95 will serve to connect Contact 92 with contact 96, Whenever; a projection 97 passes under the contact 92`- The contacts and 96 complete the signal'- c'ircuit, from ground 8S, through these contacts and lead 9'1 to' point 90. llfhe opera-y tion 'and `connectionr of all other devices,- such relays' 52 and 76, and the motorv L11, are substantially identical.' With the devices described in connectionwith the intermediate stat-ionl, and therefore'r'equire n'o further explanation. A Y llro'in the.` foregoing itl is evident that propersequence of 'they signaling' from' the various lstations is assured. The motorsffl, once' the appropriate rel'ay 52 or 76 is ener` gized, remain active until they serve to sendf in their signal by aid ofthe code wheels. Furthermore', although a system utilizing only direct current has been describe/dl, it` is evident that other kinds of current could in part or in whole be used. Furthermore, many of therrelay circuits may be varied Without substantialr variation in ultimate function of the system'. l Y A 1 rhere remains to be described a form of the device' that may be usedY` to provide the `proper mechanical' connections between the inotor, code Wheel, clutch, and contactsl associated therewith. Sur-:li an arrangement is illust-ratedy in Figs. 8 and 4l, wherein IY show base 98, which' inconjunction With a serves to house all the parte in` a neat manner. The motor 41 is secured' to'the base, and' through a train of reduction gearinj"100, is operatively connected to a shaft 101;v This shaft is journal'ed in the stand'- a'rds 102. The' code Wheel 35 which isifast# cned to one face of a collar 103,y is loosely mounted on this shaft.- Y 'y T he clutch magnet 62 is supported' onI the base 9S, as by the standard' 108, and in its deenergized condition as shown it 'permits the shaft- 1'01 to drive the' code Wheel 35. For this purpose a' collar 104 is splined in shaft '101, and is urged toward the wheel 35 by the `fxnipression spring 105. This collar'has an extending nin 1.06 which is aif'ranged to coact with aprojection such as pin 107 on the code Wheel 35, so that in the position shown the code l Wheel? may be rotated by the rotating collar 104'. The magnet 62 hovvever has a forked armature 109 which when attracted', pulls the collar 10st away from the Wheel 35 and against the force of spring' 105. rllhe armature is pivotedl on edges 110 of the member 111 forming a part of the' magnetic circuit for the clutch magnet 62. In order t-o keep the armature 109' in proper position, withvv re! spect to this meinberlin, it is 'provided With'V Furthermore a spring,` 114 approon a short extension of the armature, through Y l which passes' the spring post '115,' fastened l A to a turned-Cup lip 116 of the membenlli.` 'n lt is evident from thek foregoing that'fen'ers giza'ti'on of magnet 62 effects an immediatev uncoupling of the codeV Wheel.l fromthe shaft 101,- so that it Will be preventedfr'om transmitting' 'its signal; i The j'contacts con-i l trolled by the Wheel"asit'rotates areualso shown, and in thepr'esei'it 'instance are' ar! ranged .to be'V used at an intermt-idiate'.sta-1V tionll, Valthough minor changes may. read-= i ily bem'ade to adapt the device for use' at the end station 86. r The contactmember 37 has a' cam follower 117 Whichfis in thepa'th ofthe code Wheel segment 35 and projections-` 38,- andis fastened 4to base98 as by aid of the insulating' block 118. As soon as the segment 35 passes under this follower, and even before projections 38 pass thereunder', the

Contact member 37v is flexed'suiiiciently. to

engage the contact member 40', anda further flexing, due to the passage of the projections 38 underthe` follower 117, serves to'connect it to the contact member 36.- Thecontarcton member 37 is wide enough` to bridge-both m'e-mbers36 and 40, as clearlyshovvn'inFig, 4. rl'he contact memberstO and l36ers'` also appropriately att-ached -to' the otherv side of block'Y 118, and may be ladjusted so as to `be properly spaced from the. member 37, bythe aid of adjusting screwsV 1192 These screwsl engage" the members 36 andf 410, and'f .are threaded in upright standards k121 which may also be attached to the block 118;v .The operation of these contacts inthe system' has beenv described' 'in detail, and it is considered' not essential to set vit forth at this point;

Both' setsof contacts 59 .and 80 are ar.- ra'ng'ed to be voperated tor close as soonras the code Wheel 35 moves froinits inactivepor sition. This is accomplished by the .aid of the' cam follower 122Which slips in as'shallow depression 123 of collar 103, and is'urgred into this position by the spring1'24 fastened:l to an insulation block 125. This follower serves also, by friction, to'maintain the Wheel 35 in its inactive position if clutch magnet ards V130 may be` used in which arethreaded the adjusting screwsA 131. YIt is evident that the code wheel 35 must make a complete `revolution before the contacts 59 and 80 are permitted to open, vsince/the follower 123 y'will only then be permittedto reenter the depression 123.

, YIn order to provide a neat scheme of con? I y nections" torlthe motor 4:1. and forthe variy132 may be included in the box thebase 98 and cover 99.v

ous contacts,-a plurality ot'. binding post-s `formed by Arbrief review v of vthe operation of the y systeinmay now be set `forth. Assuming that a train or other vehicle passes station 3l from`4 right to left, 'the switch 43 Awillbe opened: .,Thisrcauses relayy 46 to. drop its-I armature, making contacts `5l; At the saine time, relay 73'is held from 'dropping itsV armature `by an interlock, so as to prevent interference vwhen' the train vreaches switch 44. .The contacts 51 complete` thecircuit for control relay 5.2.l The motor ll is energized immediately,lsince its circuit is completedby contacts 65 and.66 or" this relay. In case no distant station is active, relay 34 is ,deenergizech 4and the motor remains clutched to the code wheel, the clutch being inthe position of Fig. #1.,- After the code wheel 35 rotates through a very small angle, contacts 59 are completed and serve to shunt the contacts 51so that even ter the train passes the switch 43, a holding circuit for control relay 52 through these contacts will be Completed, which may be broken only yafter the wheel 35 makes a complete vrevolution, and has transmitted its signal.

At` that time, the contacts 59 open, relay 52 isopen-circuited, and motor 41 is dcener gized. Y Q 4 I In case relay' 311 is however energized due to the transmission of a signal from afdistant station, the. clutchVV magnet 62 is ener gized when relay 52 picks up, through both sets of contacts 6l and 63. The contacts and the clutch itself are so arranged however, that the 'clutch does not immediately respond, but permits rotation ot wieel 35 far enough to operate contacts This may be secured for eXample,`by delaying the clorsure of contacts 6 1, in'any well-known manl the relay 34 will be short--circuitediv so that signals attempted to be sent from adistant Vstation after that time willhave vno effect on the circuit for the clutch magnet 62. rWhen two signals from two separatestations are attempted to be sent substantially simultafneously, that one will be sent rst which firstcauses the vmaking of contact between 37 and 40. i Lateron, when coiitact'with member v36 is also established, the clutch forthe into the energization at thatstation ot a relay which is the equivalent of relay 34C.; It is thus seen that proper sequence ot' thesignals must be observed when my system (is used,

and confusion is satisfactorily Obviated. Y, Iclaim: Y y Y l. In a railroad `signaling system, `a plucommon receiver associated with saidltransinit-ters, each vtransmitter being adapted to be operated to effect either one oftwo char'- rality or" remote automatic transmitters,l a

Y tert'ering station is temporarily inactive, due Y acteristic responses atrthe receiver, means'as sociated with a railroad track section adjacenta corresponding transmitterrv to initiate operation of such transmitter to produce one characteristic response when a train passesY in' one direction and another characteristicl responsefwhen a train passes in another di- Y rection and means for/delaying the operation of arsubsequently initiated transmitter until termination of the signal from said first ini-V f' tiated transmitter. Y n

`2.1I'n a railway signaling system, a r`plurality of transmitters located respectively near remote sectionsof track, a circuit over which the transmitters may send a Asignal by varying` the current iiowV therein. ksaid transmitters beingl arranged in parallelfrelation lim with respect to the circuit, means associated Y,

with each transmitter responsive to the passing ot a train over its respective ysection'to actuate it, each ofl said means being constantly capable of operation, whereby substantially simultaneous operation` of saidy means can result, and means vresponsive. to the transmission of a signal by one oi the transmitters, for delaying the transmission of signals from any of the other transvmitters.

3. In a signaling` system, i plurality of transmitters, said transmitters being ar# ranged in parallel relation and adapted to y signal over ,a common medium, movable means for 'operating each transmitter.,rv and means associated with each transmitter for delaying the operation of the transmitter while n'iaintaining the operating means .in motion, until after themedium is clear.

4t. In a signalingsystcm, a plurality of transmitters, a circuit over which the transinitters may send a signal by varying the current flow therein` sources of motion, one

foreach transinitteivto cause it to' trans-v mit a signal, said source of motion being ren-Y dcred active in response to the occurrence of an'event associated with that transmitter,

Il i) and means for disconnecting the source fromY the transmitter in response to current conditions in theeircuit, while,maintainingfsaid source active, whereby the signal: may be delayed.

5. In a signaling system, aplurality o'f transmitters. aL circnitfover which the trans mitters may send aV signal by varying the current flow therein, sources of motion, one

for eachv transmitter to cause it to transmit a signal, said source ot motion heingfreiidered active in respoiise'to vthe occurrence'ot an event associated with that transmitter, and means i'or disconnect-ing the source trom:

said

the transmitter while maintaining source active and until after thecircuit is clear et signals transmitted byV other Atransmitters. A

V6. Ina signaling system, a plurality of transmitters. a circuit over which the transmitters may send a signalV by varying theV current flow-therein, souiceso't motion, one.

for each transmitter'to cause it to transmit a signal, said source of motion being rendered active in response to the occurrence et an event associatedl with that transmitter,

means Jfor maintainingr this source ot motionactive until the signal is transmitted, and means for disconnecting the source from the transmitter while maintaining said source current How therein, sources. or" motion, one

for each transmitter to cause it to transmit a signal, said source, et motion being rendered active in response to the occurrence of yan event associated with that transmitter, v

meansfior maintaining this source of motion active until the signal is vtransmitted and means for disconnecting the source from the transmitter while maintaining said source active, and until after the circuit is clear ot signals.

rality of transmitters wthvmotors driving them, automatically and separately actuated in response t-e the occurrence ot an event associated with each transmitter, and adapted to transmitsignals over a common medium, the method et1 insuring that the signals will not interfere, which comprises actuating any of the motors when the associated event occurs, maintaining said motors tion.

v9i Infa'railwaysignaling system, a circuit, more than two transmitters adaptedfto.bei

connected iii-parallel tothe circuitv at'diflierf ent points thereof and llocated respectively*I near remote track sections. a receiver located near one end of .thecircuit for receiving allot the/signals 4'from thetransmitters,'and means associated with each transmitteroperated.

independently et the receiver and responsive to the actuation ot' any one of the distant transmitters, tor disabling the transmitter distant transmitter completes its;

until a signal,

' l0.A In a railway signaling system, a circuit', more than twof transmitters adaptedztofbe coniiectedin parallel'to the circuit at i different points thereofl and located respec-L tively near remote track sections, said transivinitters beingk adapted to transniitsignals automatically in response to the passage'ot a train over a. respective track sect-ion, a` receiver ylocated near one end of 'thel circuit for receiving all of the signals yfrom the transmitters, and means associated with each transmitter operated independently of the receiver and responsiveto the actuation oit` any' oneA ofthe distant transmitters for de`- la ine' the actuation of the transn'iitter until y .s thel distant transmitter completes its signal..

ll. In a signaling system, a circu-itya 'plurality of transmitters adaptedv `to, be coii-l nected in parallel to the circuit at different points thereof, and to transmit signals auto yit and the receiver and thereby transmit ab signal, means responsive to lthe variations in current iiow for disabling the transmitters located between the transmitting station and the receiver until the transmitter completes its signal, means for completinga circuit between the transmitter and the farthest t transmitter `f or likewise disabling all the 8. In a signaling system `having a plutransmit-ters located farther from thereceiver.

l2, In a signaling system, a circuit, are-f ceiver near one end of the circuit, a plurality connected in parallel at diiiperent points along the circuit, andnnieans whereby the transmission of a signal" trom any intermediate transmitter .will cause the signalsv attempted tofbe sent from any of the other transmitters,`to be delayed, comprising electroresponsive elements included in the circordancejwit-hk the signals sent from lthe intermediate transmitter to the receiver,

vwhereby all other transmitters may Vbe affected to delay their signals.

- :13. In a signaling system, a circuit a plu-Y rality `of transmitters associated with the circuit at' dierent pointsjthereo electroresponsive devices in t'he circuit, one for' each transmitter, motors for operating the tansmitters, means for causing anyone of saidmotors to move in response tothe occurrence of an event associated with that trans` .mitter which is operated'by said vmotor,

means operated by the electro'r'esponsive device'associated with said transmitter for disconnecting the motor `from the vtransmitter for'the period in which signals are trans.

mitted from other stations, and means for maintaining the motor in motion until the transmitter isv actuated to complete its signal. Y

. 14. In a signaling system, a circuit, a plu-V rality of transmitters associated witlrtlie circuit at different points thereof, electroresponsive devices inthe circuit,y one for each transmitter, motors for operating the transmitters, means for energizing any one 0f said motors in'response to the. occurrence of an event associated with that transmitter which is operated by said motor, means for v'disconnecting the motor from theftrans-V initter, controlled by the electroresponsive device associatedivith said transmitter for `the period in which signals are transmitted from other stations, and means disabling the electroresponsive device in 'response to a small initial movement of the transmitter,v

whereby it is assured that the signal can be completed without interference from the electroresponsive device.V

15. In a signaling system, a transmitter adapted when operated to transmit a coded signal, a motor for operating the transmitter, means for causing the motor to move in response Ato an event, a clutch between the motor and the transmitter, means for'V disconnecting the clutch in response to they existence of a signaling condition in the circuit before the transmitter is active to send a signal, and means maintaining the motor in motion until the transmitter has been actuated to send its signal,v

16. In a system for transmitting a signal whenever a train passes a given point, a

code wheel, means for rotating the wheel in opposite directions yin response to oppof site directions of travel of passing trains.

17. In a system for transmitting a signal whenever a train passes a given point, -a`

code wheel, a reversible lmotor for driving the code wheel, and means responsive tothe passage of a train for energizing the motor in opposite vdirections for opposite direc-v tions of the train movement. f 18. In a signaling device, a code wheel,

motor for rotating said'code wheel, a clutch betweenthe motor and code wheel, means. normally tending to retain said clutch into operative engagement, and means adapted to be electrically energizedv to move said clutch to disengagesaid motor from said V'code wheel. A l Y f Y y y 19. In a system for transmitting a signalY whenever a train Vpasses a given .pointfa transmitter, and meansforactuati'ng the transmitter in opposite directions for opposite 'train movements, comprising a pair of controlling devicesV for thetransmitter ar@ ranged tobeoperated in succession as the Vtrain passes the point, and means'whereby the lirst deviceto be operatedrenders the other ineifective. Y

20. In a signaling system, an electric cirkcuit, a plurality of ltransmitters arranged in parallel to tliecircuit, said circuit being open during non-signaling, and said transing non-signaling,l yand said transmitters when active being arranged to closeand open the circuit*intermittently, a source of energy near each end of `the circuit, the

sources beingarranged in opposition, and

means located near each transmitter for dis# abling it, said means being arranged in series relation in the circuit, whereby `upon operation of any of the transmitters, the two sources of energy cause all ofthe disabling means associated with the other transmitters to operate. V

In testimony whereof, I have hereunto FRANK A. MILLER. 

